**1. Introduction**

Global warming is leading to increased average temperatures and irrigation difficulties in some places due to water availability affecting vineyard and wine production [1]. Wine regions affected by global warming have typical problems such as grape varieties with low acidity at harvest time, and high sugar contents that produce wines with flat taste, weak and simple aroma profile, and high alcoholic strength and pH [2]. Moreover, in red wines, the polyphenol content and especially the anthocyanins synthesis is affected, producing wines with less and more unstable colors [3]. Higher pHs make the wines less stable from a physicochemical point of view, but also more susceptible to microbial spoilage. In addition, higher pHs require strong acidity corrections, but pH is not easy to modify with tartaric acid, and wines are usually maintained at inadequate pH values. These values reduce the effectiveness of SO2 by decreasing the molecular content that is more active as antimicrobial and antioxidant. The molecular SO2 level of 0.6 mg/L has been proposed for maximum wine protection [4].
